CN115675726A

CN115675726A - Boat with retractable hydrofoil

Info

Publication number: CN115675726A
Application number: CN202210896442.3A
Authority: CN
Inventors: G·哈塞尔斯科格
Original assignee: Candra Technology Co ltd
Current assignee: Candra Technology Co ltd
Priority date: 2021-07-28
Filing date: 2022-07-28
Publication date: 2023-02-03
Also published as: US20230033965A1; JP2023021002A; EP4124559A1

Abstract

The invention relates to a ship comprising: -a hull, -a hydrofoil mounted to the hull by means of a hydrofoil retaining device comprising a strut, -wherein the vessel comprises a strut adjustment device configured to retract the strut from an extended position to a retracted position in order to move the hydrofoil from a deployed position to a restrained position and/or to lock the strut in the extended position and/or the retracted position, -wherein at least a part of the strut has a hydrodynamic portion forming a leading edge and a blunt trailing edge, wherein a shield portion of the strut adjustment device is positioned and/or configured to be positioned such that the extension of the shield portion in the longitudinal direction of the strut is located within the extension of the blunt trailing edge in the longitudinal direction of the strut and such that the shield portion is located behind the blunt trailing edge as seen in the straight forward travel direction of the vessel and/or in one or more cavities in the hydrodynamic portion, the one or more cavities extending from the blunt trailing edge.

Description

Boat with retractable hydrofoil

Technical Field

The invention relates to a vessel comprising a hull and a hydrofoil (hydrofoil) mounted to the hull by means of a hydrofoil retaining device comprising a strut. The invention also relates to a strut for mounting a hydrofoil to the hull of a ship.

Background

Hydrofoils can provide energy efficient marine transport. However, a disadvantage of such a vessel is that the hydrofoil and the structure holding the hydrofoil are easily damaged when hitting the seabed or a floating object.

WO2020056530A2 discloses a hydrofoil of a hydrofoil vessel which is folded up to be protected from collision with a floating object or the seabed. However, the actuators and linkages used to provide this collapsibility add to the complexity of the boat and therefore their cost. In case the linkage for foldability is located below the water surface, it will also increase the towing force and thus reduce the energy efficiency of the vessel.

Disclosure of Invention

It is an object of the present invention to provide a hydrofoil vessel in which the hydrofoil is protected from damage while maintaining the energy efficiency of the vessel.

This object is achieved with a vessel according to claim 1. The object is thus achieved with a vessel comprising:

a boat body and a plurality of boat bodies,

a hydrofoil mounted to the hull by means of a hydrofoil retaining arrangement comprising struts,

wherein the vessel comprises a strut adjustment device configured to retract the strut from the extended position to the retracted position in order to move the hydrofoil from the deployed position to the restrained position, and/or to lock the strut in the extended position and/or the retracted position,

wherein at least a part of the strut has a hydrodynamic portion forming a leading edge and a blunt trailing edge, wherein the shield of the strut adjustment device is positioned and/or configured to be positioned such that an extension (extension) of the shield in the longitudinal direction of the strut is located within the extension of the blunt trailing edge in the longitudinal direction of the strut and such that the shield is located behind the blunt trailing edge when viewed in the straight ahead direction of travel of the vessel and/or in one or more cavities in the hydrodynamic portion, which cavities extend from the blunt trailing edge.

The vessel may be of various types. For example, the vessel may be a powered vessel, a cruise vessel, or a vessel for commercial operations, such as a vessel carrying passengers and/or cargo, or surveillance or service. In some embodiments, the vessel may be a military vessel.

The strut adjustment device may be configured to retract the strut from the extended position to the retracted position. Alternatively or additionally, the strut adjustment means may be configured to lock the strut in the extended position. Alternatively or additionally, the strut adjustment means may be configured to lock the strut in the retracted position.

The struts may be configured to extend at least partially downward from the hull. The leading edge formed by the hydrodynamic portion may be rounded as seen in a transverse cross-section of the strut. However, in some embodiments, the leading edge formed by the hydrodynamic portion may be pointed.

The strut adjustment means may comprise a first actuation device fixed to the strut and a second actuation device engaged with or adapted to engage with the first actuation device. The strut adjustment means may further comprise a drive device adapted to apply a force to the second actuation device such that the second actuation device applies a force to the first actuation device to move the first actuation device and thereby the strut. The shielding of the prop regulating device may comprise one or more first actuating devices. In some embodiments, the shield of the prop adjustment device comprises one or more second actuation devices, or a portion of a second actuation device.

The shield may be formed by one or more parts of the strut adjustment means. The shield may be located within the extension of the blunt trailing edge along the strut. In some embodiments, the shroud of the strut adjustment device is positioned and/or configured to be positioned behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel.

In other embodiments, the shroud is positioned and/or configured to be positioned in one or more cavities in the hydrodynamic portion, the one or more cavities extending from the blunt trailing edge. In such an embodiment, preferably the one or more cavities extend from the blunt trailing edge in the straight forward direction of travel of the vessel. Thereby, the shield of the strut adjustment device may be located in front of the blunt trailing edge, as seen in the straight forward travelling direction of the vessel. In some embodiments, one or more cavities may be formed by grooves extending in the longitudinal direction of the strut.

The shroud of the strut adjustment means or one or more components thereof may exit from a position behind the blunt trailing edge and/or from one or more cavities in the hydrodynamic portion in the retracted position of the strut.

For example, as described in the examples below, the shade of the prop adjustment device may comprise a portion of a long flexible element, such as a cord or wire, that is rolled up on the winch in the retracted prop position. However, in the extended strut position, at least a portion of the elongate flexible element is positioned behind the blunt trailing edge when viewed in the straight ahead direction of travel of the vessel, and/or in one or more cavities in the hydrodynamic portion extending from the blunt trailing edge. Thereby, at least a portion of the long flexible element is configured to be positioned behind the blunt trailing edge, as seen in the straight forward direction of travel of the vessel, and/or in one or more cavities in the hydrodynamic portion, which extend from the blunt trailing edge.

Thus, the shroud of the strut adjustment means may be configured to be positioned, when the strut is in the extended position, behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel, and/or in one or more cavities of the hydrodynamic portion extending from the blunt trailing edge.

The blunt trailing edge formed by the hydrodynamic portion may be formed by one or more surfaces forming one or more angles of 60-120 degrees, preferably 70-110 degrees, relative to the chord line of the hydrodynamic portion in a transverse cross-section of the strut. For example, one or more surfaces forming the blunt trailing edge may be perpendicular to the chord line of the hydrodynamic portion. One or more surfaces forming the blunt trailing edge may extend along the strut. The chord line may coincide with a line of symmetry of the hydrodynamic portion. The chord line may extend from the leading edge to the midpoint of the blunt trailing edge. Preferably, the surface or surfaces forming the blunt trailing edge are straight as seen in a transverse cross-section of the strut. Alternatively, one or more surfaces forming the blunt trailing edge may be curved.

Preferably, one or more surfaces forming the blunt trailing edge form corners with corresponding side surfaces of the hydrodynamic portion as seen in a transverse cross section of the strut. The corners may be formed by surfaces oriented at an angle of 70-110 degrees with respect to each other. The corner may have a small radius, for example less than 1/10 of the width of the blunt trailing edge. Thus, the corners may be harsh. Thereby, a separation of the water flow past the side surfaces of the hydrodynamic part will be provided at the corners. Thus, a cavity will be created behind the blunt trailing edge, as described below.

The shroud is positioned and/or configured to be positioned within the extension of the blunt trailing edge along the strut. That is, the shield is positioned and/or configured to be positioned within the extension of the blunt trailing edge in the longitudinal direction of the strut. Thus, when the vessel is travelling straight ahead, the vertical extension of the shelter of the strut adjustment means may be located within the vertical extension of the blunt trailing edge.

Preferably, at least a portion of the shroud of the strut adjustment arrangement is positioned to lie below the water surface when the vessel is travelling straight on still water in hydrofoil mode. Thereby, a part of the shelter may be positioned above the water surface when the vessel is travelling straight on standing water in hydrofoil mode.

Preferably, the shielding portion of the strut adjustment means extends transverse to the chord line of the hydrodynamic portion and transverse to the longitudinal axis of the strut or is configured to extend transverse to the chord line of the hydrodynamic portion and transverse to the longitudinal axis of the strut no further from the chord line than the extension of the blunt trailing edge in a direction transverse to the chord line and transverse to the longitudinal axis of the strut. Thus, the shroud portion of the strut adjustment means may be located within an extension of the surface or surfaces formed by the blunt trailing edge, the extension being transverse to the chord line of the hydrodynamic portion. Thereby, the shielding portion of the strut adjusting means does not extend further than the blunt trailing edge in the width direction of the blunt trailing edge. Thus, the shield is located within the lateral extension of the post.

As will be appreciated from the above, in some embodiments the shroud portion of the strut adjustment device is located or configured to be located behind the blunt trailing edge when viewed along the chord line in a direction from the trailing edge towards the leading edge. Preferably, the shielding of the strut adjustment means is located completely or configured to be located within a maximum distance from the blunt trailing edge of 300%, preferably 200%, preferably 100%, preferably 50%, preferably 30%, preferably 20% of the extension of the hydrodynamic portion along the chord line of the hydrodynamic portion. The shroud of the strut adjustment means may be distributed behind the trailing edge along the extension of the chord line.

With a blunt trailing edge, the struts can form a ventilation profile. The struts may be a base ventilation profile. In some embodiments, the struts may form a supercavity profile. In this regard, the base vent section may be provided with a base cavity that is vented to atmosphere. The cavity created behind the blunt trailing edge may form an air channel down the strut from the atmosphere. The blunt trailing edge reduces the risk of venting of components of the section between the leading edge and the trailing edge. A necessary condition for aeration is flow separation. Conversely, a precondition for flow separation is that the flow velocity decreases along the profile, as seen from the strut. The velocity of the water increases with the thickness of the profile. The maximum velocity can be reached approximately at the location where the profile has its maximum thickness. Downstream of this location, the velocity is reduced. Thereby, the flow runs the risk of separation. If there is access to the air, for example because the struts extend upwards and above the water surface, there is a risk that air will be sucked into the cavity created by the separate flows. Thereby, ventilation occurs. The problem with ventilation is that it often occurs suddenly and usually only on one side. Then most of the negative pressure on the ventilation side will be lost. This generates a force in the transverse direction of the vessel. In case the struts are located at or near the stern of the vessel, this ventilation may create a yawing moment. With the struts closer to the center of gravity of the vessel, this ventilation may create a roll moment.

This venting can be avoided by using a blunt trailing edge. Instead, a stable air pocket or plenum can be formed behind the strut using a vent profile.

Furthermore, the ratio of bending stiffness to water resistance of the vent profile may be better than a conventional profile, such as a similarly scaled conventional profile.

In an embodiment of the invention, the sheltering part of the strut adjustment device is sheltered from the free water flow when the vessel moves forward. Thus, the invention allows the sheltering part of the strut adjustment device to be located in the wake formed by the strut when the vessel moves forward. The invention thus allows the use of one or more cavities in the space behind the profile or blunt trailing edge for the shroud of the strut adjustment means. This position means that the one or more components do not affect the water resistance. That is, an air cavity formed behind and/or in one or more cavities in the blunt trailing edge is used to adjust the device to the post without affecting water flow.

One or more components of the strut adjustment means are located behind and/or in one or more cavities in the blunt trailing edge to reduce drag on the boat, which is useful at boat speeds above 45 knots and at lower speeds. Thus, in embodiments of the invention, the vessel may have a maximum speed of less than 40 knots, for example less than 35 knots. However, the maximum speed of the vessel may be greater than 15 knots, for example greater than 18 knots.

The ability to retract the stanchion from the extended position to the retracted position allows operation in shallow water for beach landing and/or placement of the vessel on a trailer. The retractability also allows the hydrofoil to be protected from the growth of sea weeds and the like, which may compromise the efficiency of the vessel. The retraction capability may further allow for a semi-wing or pure planing mode (planing mode) where the wings are higher to reduce strut drag while still providing some lift to reduce hull drag.

As will be appreciated, one or more components of the strut adjustment means are located behind the blunt trailing edge and/or in one or more cavities in the blunt trailing edge, enabling retractability without causing increased drag on the vessel.

One or more parts of the strut adjustment means may extend along the strut by being positioned to lie behind and/or in one or more cavities in the blunt trailing edge when viewed in the straight forward direction of travel of the vessel. Thereby, the shielding portion of the stay adjusting device can be brought close to the stay. The strut adjustment device may be configured to retract the strut by moving the strut along the longitudinal axis of the strut. Thus, the strut may be configured to be retracted without rotation. This, in combination with having the shroud of the strut adjustment means positioned or configured to be positioned behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel and/or in one or more cavities in the blunt trailing edge, enables a short moment arm of the strut adjustment means.

Such a short moment arm will reduce the complexity and/or weight of the strut adjustment means. The light weight will help to maintain the energy efficiency of the ship. The invention thus makes it possible for a simple embodiment of the strut adjustment device to protect the hydrofoil from damage while maintaining the energy efficiency of the ship.

Furthermore, the struts are configured to be retracted without rotation, allowing adjustment from the retracted position to the extended position and vice versa when the vessel is moving. Thereby, the hydrofoils may maintain substantially the same angle of attack when moving from the restrained position to the deployed position, and vice versa. In contrast, with a foldable/rotatable mechanism, a hydrofoil may exhibit an angle of attack at which it results in a strong drag and/or a strong vertical force when rotated from one position to another.

Preferably, all components of the strut adjustment means which are configured to be below the water surface when the vessel is travelling in the hydrofoil mode are located behind the blunt trailing edge when viewed in the direction of straight forward travel of the vessel and/or are located in one or more cavities of the hydrodynamic portion which extend from the blunt trailing edge. Preferably, in the hydrofoil mode, the hull is lifted out of the water.

Thereby, the shelter of the strut adjustment means may comprise all parts of the strut adjustment means configured to be below the water surface when the vessel is travelling in hydrofoil mode.

The components of the strut adjustment device configured to be below the water surface when the vessel is traveling in hydrofoil mode may form the wet end of the strut adjustment device. The wet end may be a location of the strut adjustment arrangement that is configured to be below the water surface when the vessel is travelling straight ahead in hydrofoil mode and on still water. Thus, another feature that defines the wet end may be that the boat is traveling at maximum engine or motor power. Another feature that defines the wet end may be the maximum weight that the ship loads. The requirement for the hydrofoil mode may be that the entire hull is above the water surface. Thus, preferably, the wet portion of the strut adjustment device is positioned and/or configured to be positioned behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel, and/or in one or more cavities in the hydrodynamic portion extending from the blunt trailing edge.

In other embodiments, the shelter of the strut adjustment arrangement comprises a static immersion of the strut adjustment arrangement configured to be below the water surface when the vessel is statically floating in still water. Thus, a further feature defining a stationary submerged portion may be that the vessel is loaded at its maximum weight. A further feature defining the stationary immersion part may be the extended position of the support pillar. Thus, preferably the static submerged portion of the strut adjustment means is positioned and/or configured to be positioned behind the blunt trailing edge when viewed in the straight ahead direction of travel of the vessel, and/or in one or more cavities in the hydrodynamic portion extending from the blunt trailing edge.

In some embodiments, the vessel comprises a propeller arrangement mounted to the strut. Thus, when the boat is floating at rest, the blunt trailing edge may end above the vertical extension of the propeller disc formed by the propeller arrangement. Below the blunt trailing edge, the struts may have a sharp trailing edge. Thereby, the air pocket formed behind the blunt trailing edge cannot reach the propeller device. Thereby, air can be avoided from interfering with the operation of the propeller. The propeller arrangement may comprise one or more propellers. The propeller disc may be formed by the swept area of the blades of the propeller arrangement. In case the propeller arrangement comprises more than one propeller, e.g. two coaxial propellers, the propeller disc may be seen as the propeller disc of one of the propellers. In the case of propellers having unequal sized discs, the blunt trailing edge may terminate above the vertical extension of the largest propeller disc.

Preferably, the vessel is configured such that the blunt trailing edge extends from below the water surface to above the water surface when the vessel is travelling straight on standing water in hydrofoil mode. The blunt trailing edge may thereby extend above the wet end of the strut adjustment means.

Preferably, the shield portion of the prop regulating means comprises a first engagement device, wherein the prop regulating means comprises a second engagement device configured to engage with the first engagement device to lock the prop in the retracted position. Thus, one or more components of the strut adjustment means positioned rearward of the blunt trailing edge and/or in one or more cavities in the blunt trailing edge may comprise a first engagement device, wherein the strut adjustment means comprises a second engagement device configured to engage with the first engagement device to lock the strut in the retracted position. The shielding part of the prop regulating device may further comprise a further first engagement device. The second engagement device may be configured to engage with another first engagement device to lock the strut in the extended position. Thus, the prop adjustment device may comprise a locking device for locking the prop in the retracted position, and preferably in the extended position.

Thereby, one or more first engagement devices for locking the stay may be located directly on the stay. This allows the strut locking device to have no moment arm or a short moment arm, which allows for a simple or lightweight construction of the locking device.

The first engagement means may be provided in the form of a locking projection extending from the blunt trailing edge. The locking protrusion may comprise a recess or through opening configured to receive the movable male engagement element of the second engagement device. A plurality of such locking projections may form a ridge rising from and extending along the blunt trailing edge. More generally, two first engagement devices may be distributed along the blunt trailing edge, whereby the second engagement device is configured to engage with one of the first engagement devices to lock the strut in the retracted position and with the other of the first engagement devices to lock the strut in the extended position.

In some embodiments, the first engagement device comprises a recess in the blunt trailing edge configured to receive the movable male engagement element of the second engagement device. Alternatively, the first engagement device may comprise a male engagement element mounted to the strut, and the second engagement device may comprise a movable element having a recess configured to receive the male engagement element.

Whatever the embodiment of the strut adjustment means, the one or more first engagement devices are preferably configured to be located behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel, and/or more particularly, in one or more cavities in the blunt trailing edge.

As suggested, in some embodiments, the shroud of the strut adjustment device comprises at least a portion of a long flexible device, such as a cord, wire, or cable, that extends along a blunt trailing edge. Thereby, one or more components of the strut adjustment arrangement positioned behind the blunt trailing edge and/or in one or more cavities in the hydrodynamic portion extending from the blunt trailing edge, as seen in the straight ahead direction of travel of the vessel, may comprise at least a portion of the long flexible device extending along the blunt trailing edge, wherein the strut is configured to be retracted from the extended position to the retracted position by being pulled by the long flexible device. Thus, the strut may be configured to be retracted from the extended position to the retracted position by being pulled by the long flexible device. Thereby, the stay may be pulled along the longitudinal extension of the stay.

A long flexible device may be engaged with the strut for said pulling of the strut. The elongate flexible element may be engaged with a fastening element secured to the post. The fastening elements may be in the form of protrusions having openings therein. Thereby, the long flexible element may extend through the opening to be fastened to the protrusion. The projections may be in the form of brackets, ridges, staples, or the like. The protrusion may protrude from the blunt trailing edge. For example, a ridge having a recess or through hole for locking the strut in the retracted and extended positions may be raised from the blunt trailing edge and may extend along the blunt trailing edge. Thereby, a long flexible device can be fastened to the ridge below the recess or through hole.

The protrusion may form a first actuation device as referred to herein, and the elongate flexible element may form a second actuation device as referred to herein. The capstan for the long flexible element may form what is referred to herein as a drive device.

In an alternative embodiment, the shield of the strut adjustment means comprises teeth distributed along a blunt trailing edge, for example forming a rack. Thus, a motorized toothed pinion secured to the strut retention assembly may be configured to engage and rotate with the strut teeth to drive the strut up or down. The teeth distributed along the blunt trailing edge may form what is referred to herein as a first actuation device. The teeth of the pinion gear may form what is referred to herein as a second actuation device. The remainder of the electrically driven toothed pinion may form what is referred to herein as a drive apparatus.

The vessel may comprise a first hydrofoil mounted to the hull by means of a first hydrofoil retaining device and a second hydrofoil mounted to the hull by means of a second hydrofoil retaining device. The first and/or second hydrofoil may be a hydrofoil as described above and the first and/or second hydrofoil retaining means may be a hydrofoil retaining means as described above. Thereby, the second hydrofoil retaining means may be separate from the first hydrofoil retaining means. The first hydrofoil retention means may comprise one or more first hydrofoil struts. The first hydrofoil strut and/or the second hydrofoil strut may be configured to extend at least partially downwardly from the hull when the vessel is floating in the erect condition. The first and/or second hydrofoil struts may extend straight vertically or at a non-zero angle relative to a vertical axis. The first hydrofoil and/or the second hydrofoil may be secured to the respective strut.

In some embodiments, the second hydrofoil strut and/or the one or more first hydrofoil struts are configured to be pulled at least partially downward from the retracted position to the extended position by the respective long flexible apparatus. In other embodiments, the second hydrofoil strut and/or one or more first hydrofoil struts may be configured to move from the retracted position to the extended position solely by gravity.

The second hydrofoil may be located behind the first hydrofoil when viewed in the direction of straight forward travel of the vessel. Alternatively, the second hydrofoil may be located forward of the first hydrofoil when viewed in the direction of straight forward travel of the vessel.

This object is also achieved by a prop according to claim 8. This object is therefore achieved by a strut for mounting a hydrofoil to the hull of a ship. The strut comprises one or more components for a strut adjustment means configured to retract the strut from an extended position to a retracted position in order to move the foil from the deployed position to the restrained position, and/or to lock the strut in the extended position and/or the retracted position. At least a portion of the strut has a hydrodynamic portion forming a leading edge and a blunt trailing edge, wherein one or more components for the strut adjustment means are located on a side of the hydrodynamic portion including the blunt trailing edge in a chord line direction of the hydrodynamic portion and/or are located in one or more cavities in the hydrodynamic portion extending from the blunt trailing edge. The one or more components for the strut adjustment device may be positioned and/or configured to be positioned such that an extension of the one or more components for the strut adjustment device in the longitudinal direction of the strut is within an extension of the blunt trailing edge in the longitudinal direction of the strut. By locating one or more components for the strut adjustment means on the side of the hydrodynamic portion comprising the blunt trailing edge, when the strut is mounted to the hull, one or more components for the strut adjustment means may be located behind the blunt trailing edge when viewed in the straight ahead direction of travel of the vessel.

Advantageous embodiments are defined in claims 9 to 11.

For example, the object is achieved with a strut for mounting a hydrofoil to the hull of a vessel, wherein at least one location of the strut has a hydrodynamic portion forming a leading edge and a blunt trailing edge, wherein the strut has one or more cavities in the hydrodynamic portion extending from the blunt trailing edge, the one or more cavities being adapted to house one or more components for a strut adjustment device configured to retract the strut from an extended position to a retracted position in order to move the hydrofoil from a deployed position to a restrained position, and/or to lock the strut in the extended position and/or the retracted position.

A second aspect of the invention provides a vessel comprising:

a ship body is arranged on the ship body,

a first hydrofoil mounted to the hull by means of a first hydrofoil retaining device,

a second hydrofoil mounted to the hull by means of a second hydrofoil retaining arrangement, the second hydrofoil retaining arrangement comprising a strut separate from the first hydrofoil retaining arrangement, the strut being configured to extend at least partially downwardly from the hull, the second hydrofoil being secured to the strut,

a torque generating assembly, and

a propeller arrangement configured to be driven by the torque generating assembly,

in which the propeller arrangement is mounted to a strut,

wherein the second hydrofoil strut is configured to be retracted from the extended position to a dry position in which the propeller arrangement and the second hydrofoil are above the water surface when the vessel is floating at rest, wherein the configuration of retracting the strut from the extended position to the dry position comprises configuring the strut to move along a longitudinal axis of the strut.

By configuring the strut to retract from the retracted position to the drying position, fouling of the propeller arrangement and the second hydrofoil may be avoided. More specifically, the risk of growth and corrosion on the second hydrofoil at standstill is reduced or eliminated. Moreover, any of the extended, retracted and drying positions may be reached by moving the post along the longitudinal axis of the post. Thus, a single strut adjustment device can be used to achieve all three positions. This enables a relatively simple assembly for the adjustment of the prop.

For a marine vessel, such as a cruise vessel, the forward mode may be changed from the drainage mode to the planing mode if there is sufficient power capacity for propulsion thereof. With hydrofoils, the vessel can assume a hydrofoil forward mode. During hydrofoil mode, the hull is lifted out of the water. Thereby, the propulsion power requirements may be reduced.

However, when the waves are large, the hydrofoil vessel may encounter a problem in that the waves strike the hull lifted by the hydrofoil, which may cause discomfort to the people on the vessel and also cause the speed of the vessel to be so greatly reduced that the hydrofoil cannot continue to support its hull. Furthermore, when the hydrofoil vessel is not in hydrofoil mode, its draft is relatively large and can cause problems when travelling in shallow water, such as when docking the vessel.

Preferably, the strut is configured to retract from the extended position to the retracted position so as to move the propeller arrangement from the deployed position to a constrained position in which the propeller arrangement is positioned submerged in water carrying the vessel, wherein the propeller arrangement is located more downwardly in the deployed position than in the constrained position, wherein in the extended position and in the retracted position the strut together with the propeller arrangement is configured to rotate relative to the vessel hull so as to steer the vessel.

Thereby, the propeller arrangement may be kept under water for the planing mode of the ship. Thereby, the strut, the second hydrofoil and the propeller arrangement can be extended and retracted to generate thrust and provide steering capability of the vessel in the hydrofoil mode of the vessel and in the planing mode of the vessel.

The planing mode may be useful in sea wave conditions, where the waves may strike the hull of the vessel if the vessel is in hydrofoil mode. The second hydrofoil may be configured to be submerged in the surrounding water in the restrained position. Thus, in planing mode, the second hydrofoil may be used to lift the stern of the ship, which may reduce the drag of the ship. Thus, the ship can travel with high power efficiency in the planing mode as well as in the hydrofoil mode.

The second hydrofoil strut may be configured to retract from a retracted position to a dry position in which the propeller arrangement and the second hydrofoil are above the water surface when the vessel is floating at rest.

The strut may be retractable along the strut longitudinal axis by configuring the strut to move along the strut longitudinal axis. In this regard, the struts may be retracted without rotation. For example, where the strut is pivotally connected to the hull by means of a strut pivot bearing assembly, a strut retaining assembly, for example comprising one or more strut retaining brackets, may be connected to the strut pivot bearing assembly. Thus, the post holding assembly may be rotatable. Thus, the strut retaining assembly may retain the strut laterally and may be rotatable to turn the strut for steering of the vessel. For retraction, the strut may be moved relative to the one or more brackets along the strut longitudinal axis.

The struts are configured to be retracted without rotation, allowing adjustment from a retracted position to an extended position and vice versa as the vessel moves. Thereby, the hydrofoils may maintain substantially the same angle of attack when moving from the restrained position to the deployed position, and vice versa. In contrast, with a foldable/rotatable mechanism, a hydrofoil may present an angle of attack at which it results in a strong drag and/or a strong vertical force when rotated from one position to another.

Preferably, the second hydrofoil is fixed to the second hydrofoil strut at a position extending in the longitudinal direction of the strut, which position is within the extension of the propeller arrangement extending in the longitudinal direction of the strut. Thereby, the second hydrofoil and the propeller arrangement may be in substantially the same position along the strut. Thereby, the described benefits of the propeller arrangement and the second hydrofoil in the retracted position of the strut, i.e. in the planing mode of the vessel, may be obtained while minimizing the combined vertical extension of the propeller arrangement and the second hydrofoil. Hereby, the draught of the vessel in planing mode can be limited. Furthermore, for the dry position of the mast, the required distance between the water surface and the mast lift can be kept low due to the limited vertical extension of the combination of the propeller arrangement and the second hydrofoil.

The torque generating assembly may be of any suitable type. For example, it may comprise one or more internal combustion engines, one or more electric motors, or one or more hydraulic motors. In some embodiments, the torque generating assembly may be, for example, a hybrid powertrain system including one or more internal combustion engines and/or one or more electric motors and/or one or more hydraulic motors.

The strut to which the second hydrofoil is secured is also referred to herein as the second hydrofoil strut. The struts are configured to extend at least partially downwardly from the hull when the vessel is floating in an upright position. The struts may extend straight vertically or at a non-zero angle to the vertical axis.

The propeller arrangement may comprise one or more propellers. The one or more propellers may be non-ducted or ducted. The rotational axis of the one or more propellers may be fixed relative to the strut. The propeller arrangement may be mounted to the lower end of the strut. However, in some embodiments, the propeller arrangement may be mounted above the lower end of the strut.

The second hydrofoil may be secured to the lower end of the strut. However, in some embodiments, the second hydrofoil may be secured above the lower end of the strut.

In some embodiments, the strut is retractable from an extended position to a retracted position. In the extended position of the strut, the second hydrofoil is in the deployed position, and in the retracted position of the strut, the second hydrofoil is in the restrained position. The second hydrofoil is located more downwards in the deployed position than in the restrained position, just like the propeller arrangement. The relationship of the propeller arrangement or the second hydrofoil in the deployed position more downwards than in the restrained position should be understood in the case of a vessel floating in an upright position.

Thus, in the extended position as well as in the retracted position, the strut together with the propeller arrangement may be rotated relative to the hull in order to steer the ship. The ability of the strut to rotate or swivel relative to the hull to steer the vessel may be provided by means of a strut swivel bearing assembly comprising one or more strut bearings whereby the strut is pivotably connected to the hull such that the strut and propeller arrangement can be swiveled relative to the hull to steer the vessel. The strut slew bearing assembly may be connected to the hull via a strut mounting means for mounting the strut to the hull. Thus, the second hydrofoil retaining means may comprise, in addition to the strut, a strut rolling bearing assembly and a strut mounting means.

It should be noted that in some embodiments, in the restrained position, the second hydrofoil is configured to be above the water when the vessel is in the planing mode. To this end, the second hydrofoil may be fixed to the strut above the propeller arrangement.

Preferably, the first hydrofoil retaining means for mounting the first hydrofoil to the hull is configured to retract from the extended position to the retracted position, thereby moving the first hydrofoil from the deployed position to the restrained position, wherein the first hydrofoil is located further down in the deployed position than in the restrained position.

Preferably, in the restrained position, the first hydrofoil moves away from the water passing through the vessel as the vessel moves. In the restrained position, the first hydrofoil may be placed in a recess of the hull. The recess may be open downward. The first hydrofoil may move up into the recess when the first hydrofoil retaining means is retracted.

In some embodiments, the first hydrofoil is configured to be submerged in the restraint position. Thus, the restrained position can be used for the half-wing mode of the ship. In the half-wing mode, the hydrofoils can generate lift to reduce the hull friction against the water. The half-wing mode may be useful in billows. In this regard, the first hydrofoil may be in a first restrained position in which it is partially deployed and configured to be submerged, and in a second restrained position in which it is out of the water passing through the hull during travel. The first restraint position may be used for the wing-half mode and the second restraint position may be used for the taxi mode.

For such embodiments, when the first hydrofoil is in the first restraint position, the second hydrofoil may also be in a first restraint position in which it is partially deployed and configured to be submerged, and in a second restraint position in which it is still submerged but above the first restraint position. Thus, the first restraint position of the second hydrofoil may be used in the half-foil mode and the second restraint position of the second hydrofoil may be used in the taxi mode.

However, in some embodiments, the first hydrofoil may be movable to a unique restrained position, for example, for a half-wing mode. In this regard, the second hydrofoil may be movable to the only restrained position as for the half-foil mode.

In some embodiments, the first hydrofoil retaining means comprises one, two or more struts extending at least partially downwardly from the hull. Such a strut is also referred to herein as a first hydrofoil strut.

The second hydrofoil may be located behind the first hydrofoil when viewed in the straight forward direction of travel of the vessel. Alternatively, the second hydrofoil may be located in front of the first hydrofoil when viewed in the straight forward direction of travel of the vessel. In case the first hydrofoil retaining arrangement comprises one, two or more first hydrofoil struts and the first hydrofoil retaining arrangement is configured to retract, the one or more first hydrofoil struts may be configured to move along a respective longitudinal axis of the first hydrofoil strut. Thereby, the first hydrofoil retaining means may be configured to be retracted by lifting the one or more struts along their longitudinal axis. In this regard, the first hydrofoil retaining means may be retracted without rotation. In other embodiments, one or more first hydrofoil struts are retracted by being folded.

In case the first hydrofoil is configured to retract, the first hydrofoil may be above the water surface in the restrained position when the vessel is floating at rest. Thereby, the risk of growth and erosion of the first hydrofoil at standstill is reduced or eliminated. This may be achieved by a recess in the hull which is deep enough to allow the first hydrofoil to move above the water surface. The recess may be adapted to form a step in the hull. Such steps may be used to allow air lubrication of the hull when the boat is traveling in planing mode.

The torque generating assembly and the propeller arrangement may form part of a propulsion arrangement. Preferably, the propulsion device is provided in the form of a motor compartment.

Preferably, therefore, the propeller device and the torque generating assembly form part of a motor nacelle fixed to the second hydrofoil strut. The strut and the motor compartment are thereby configured to rotate relative to the hull in order to steer the vessel. The motor compartment may include a housing, a torque-generating assembly disposed in the housing, and a propeller arrangement configured to be driven by the torque-generating assembly. As understood when the vessel is travelling forwards, the propeller arrangement may be located upstream or downstream of the second hydrofoil strut. I.e. the propeller device may be pulled or pushed. The propeller arrangement may comprise two contra-rotating propellers.

By including the torque generating assembly in a motor nacelle fixed to the second hydrofoil strut, there is no need to include a drive shaft in the strut for transmitting power to the propeller arrangement. Thereby, it is facilitated to move the strut to retract it to the retracted position and to move the strut away from the retracted position towards the extended position.

Preferably, the torque generating assembly comprises one, two or more electric motors. Thereby, the power for the torque generating assembly may be transferred through one or more cables extending through the second hydrofoil strut. The power may be provided by a battery pack, which may be provided in the hull. The one or more cables are preferably flexible. Thereby, the cable may bend when the strut is moved to and from the retracted position.

The second hydrofoil and the motor bucket may be in substantially the same position along the second hydrofoil strut. Thereby, the wings of the second hydrofoil may extend from opposite sides of the motor compartment. However, in some embodiments, the second hydrofoil and propeller arrangement are located at different positions along the strut. For example, the second hydrofoil may be fixed to the strut above the propeller arrangement. For example, where the strut comprises a lower strut part and an upper strut part, the second hydrofoil may be mounted to the strut between the lower strut part and the upper strut part and the propeller device mounted to the lower strut part. In other embodiments, the propeller arrangement is fixed to the strut above the second hydrofoil.

As suggested, one or more of the second hydrofoil strut adjustment means may comprise a long flexible device. The or each long flexible device may be secured to a respective strut. A drum or wheel driven by a drive device, such as a motor, may be configured to engage the long flexible device to pull up the stanchion. The drum and the drive device may form a winch. Such a drum or wheel may be fixed to the strut holding assembly, configured to hold the strut laterally, and rotatable in order to turn the strut to steer the vessel.

It should be noted that in some embodiments, the mechanical power may be transmitted to the propeller arrangement through a shaft inside the strut and extending in the longitudinal direction of the second hydrofoil strut. Thereby, the torque generating assembly may be fixed to the upper end of the strut.

Preferably, the hull has a stern edge configured such that water in contact with the hull in planing mode of the vessel is detached from the hull at the stern edge, wherein in the retracted position of the second hydrofoil strut the second hydrofoil is located aft of the stern edge when viewed in a straight forward direction of travel of the vessel. The stern edge may be transverse or at least partially transverse when viewed in the direction of straight forward travel of the vessel. Thereby, the centre of lift acting on the vessel in the planing mode of the vessel can be relatively far forward. This means that said centre of lift of the reference hull in planing mode can be relatively close to the centre of lift of the reference hull acting on the hydrofoil in hydrofoil mode of the vessel. Thus, the movement of the lifting center when transitioning between these modes may be relatively small. Preferably, the distance from the centre of gravity of the vessel to the stern edge is no more than 90% of the distance from the centre of gravity of the vessel to the second hydrofoil.

Other variations are possible. For example, when the vessel is travelling straight in hydrofoil mode, the propeller arrangement may be configured to be more submerged than the first hydrofoil. In other embodiments, the propeller arrangement may be configured to be located at substantially the same depth as the first hydrofoil when the vessel is travelling straight ahead in hydrofoil mode. The first hydrofoil may be a submerged hydrofoil or a hydrofoil that passes through the water surface.

In order to reduce the complexity and cost of a motor bay driven boat, a third aspect of the invention provides a boat as follows:

a vessel, comprising:

a ship body is arranged on the ship body,

and a motor compartment and a submersible structure, wherein the motor compartment is mounted to the hull by means of the submersible structure,

wherein the motor compartment comprises a torque generating assembly and a propeller arrangement configured to be driven by the torque generating assembly,

wherein the motor compartment further comprises a housing, wherein the torque generating assembly is disposed in the housing,

wherein the housing includes a recess, and the submersible structure extends into the recess of the housing,

wherein the submersible structure comprises a foil partially surrounding the housing and a further element partially surrounding the housing such that the further element and the foil together completely surround the housing, wherein the further element and the foil are fastened to each other.

The housing may have a long shape. The housing may extend along the rotational axis of the propeller arrangement. The housing may extend in the direction of thrust generated by the propeller arrangement. The housing may be hollow to house the torque generating assembly. By including the torque generating assembly in the motor bay, the motor bay is mounted to the hull by means of the submersible structure, without the need to include a drive shaft in the submersible structure for transmitting power to the propeller arrangement. Preferably, the torque generating assembly comprises one, two or more electric motors. Thus, power for the torque generating assembly may be transferred through one or more cables extending through the submersible structure. The motor compartment housing may be provided with one or more through holes, e.g. by milling, through which the cables extend from the interior of the housing to the interior of the submersible structure. Power may be provided by a battery pack, which may be provided in the hull.

By means of the submersible structure extending into the recess of the motor compartment housing, the housing can be locked in the longitudinal direction of the motor compartment. Thereby, the motor compartment may be securely fixed to the submersible structure.

The housing recess enables the housing to be secured to the submersible structure by mechanical engagement between the housing and the submersible structure. So that the manufacture of the combination of the housing and the submersible structure can be facilitated. More specifically, it is easy to integrate different materials for these components. For example, the submersible structure may be made of a lightweight composite material, such as a fibre reinforced plastics material. The housing may be made of metal, for example copper or stainless steel. The housing recess allows these components, which are made of different materials, to be assembled simply.

Thus, a strong engagement of the housing to the submersible structure is provided, while easy assembly of these components is achieved without manufacturing complexity. Thereby, the complexity and cost of the motor bay driven boat may be reduced.

The recess may be provided as a waist in the housing. The housing or one or more parts of the housing may have a cylindrical shape. For example, the portions of the housing on both sides of the recess may be cylindrical in the longitudinal direction of the housing. Thereby, the waist forming the recess may be formed by the portion of the housing having the reduced diameter. Thus, the shell may be manufactured on a lathe to form a turned tube. Thereby, the manufacture of the motor compartment is simplified and thus cheaper. Thus, structural efficiency is combined with manufacturing advantages.

The axis of rotational symmetry of the housing may be coaxial with the axis of rotation of the propeller arrangement. Furthermore, the housing may be formed cylindrically in the recess.

Preferably, along at least one location of the circumference of the housing, the extension of the submersible structure in the longitudinal direction of the housing is the same as the extension of the recess in the longitudinal direction of the housing. Thereby, at the end of the recess in the longitudinal direction of the housing, the submersible structure may have a boundary in the radial direction of the housing immediately outside the recess, which is the same as the boundary of the housing in the radial direction. Thereby, a smooth transition of the outer surface of the housing to the outer surface of the submersible structure may be provided.

The foils and the other elements are preferably fastened to each other in a detachable manner. Alternatively, the hydrofoil and the other elements may be fastened to each other in a non-detachable manner, for example by means of an adhesive or rivets.

The submersible structure may comprise a hydrofoil retention means. Thereby, the hydrofoil may be mounted to the hull by means of the hydrofoil retaining device. The hydrofoil may be a submerged hydrofoil, or a hydrofoil that passes through the water surface.

The hydrofoil retention means may comprise a strut. Thereby, the hydrofoil can be mounted to the hull by means of the strut. For example, the other element may be a strut. The struts may be configured to extend at least partially downward from the hull. The hydrofoil and the motor bucket may be at substantially the same position along the strut. Thereby, the wings of the hydrofoil may extend from opposite sides of the motor bucket. The wing portions may be cantilevered. As understood when the vessel is travelling forward, the propeller arrangement may be located upstream or downstream of the strut. That is, the propeller device may be a pulling device or a pushing device.

The struts may partially surround the housing. The struts may partially surround the housing in a circumferential direction of the housing. The struts may form a hydrodynamic profile having a chord line. Thus, the housing longitudinal axis may be substantially parallel to the chord line. The motor compartment may be mounted to the lower end of the strut. However, in some embodiments, the motor compartment may be mounted above the lower end of the strut.

In the case of a strut partially surrounding the housing, the hydrofoil may partially surround the housing such that the strut and hydrofoil together completely surround the housing. In this regard, the hydrofoil may partially surround the shell in a circumferential direction of the shell. The struts and foils may be fastened to each other. In this regard, the strut and the hydrofoil may be fastened to each other in a detachable manner, for example by means of bolts, or in a non-detachable manner, for example by means of an adhesive or rivets.

Preferably, the hydrofoil and other elements extend into a recess of the housing. For example, the struts and foils may extend into recesses in the housing. Thereby, the struts and the hydrofoils may completely surround the housing while extending into the recess of the housing.

In some embodiments, the struts form a fork or partial circle to partially surround the housing. In this regard, the dividing line between the strut and the hydrofoil may be horizontal when the vessel is floating at rest. However, in some embodiments, the dividing line between the strut and the hydrofoil may be at an angle greater than 0 degrees and less than or equal to 90 degrees relative to horizontal.

As suggested, the recess may be provided as a waist in the housing. To secure the motor compartment to the strut, the lower end of the strut may form a part circle or fork that at least partially surrounds the housing in the waist. The hydrofoil may extend from one tip end to the other, with the motor bucket and strut between the tips. Thereby, the hydrofoil may be provided as a single piece extending between the two wing tips. Thereby, the hydrofoil may extend into the recess of the housing. Thereby, the hydrofoil may comprise a curved portion for partially surrounding the housing. The strut and the second hydrofoil may be connected on opposite sides of the motor bucket, for example by bolts or similar removable fasteners, or by adhesive or other non-removable fastening means.

In some embodiments, the further element is a cabin securing arrangement partially surrounding the housing, such that the hydrofoil and the cabin securing member together completely surround the housing, wherein the hydrofoil and the cabin securing member are fastened to each other. The hydrofoil may be mounted to the hull by means of a hydrofoil retaining device. However, in some embodiments, the submersible structure does not include any hydrofoil retention devices. For example, the submersible structure may comprise a hydrofoil extending directly from the hull through the water surface, e.g. a hydrofoil extending partially down and partially towards or away from the plane of symmetry of the hull through the water surface.

Where the submersible structure comprises a strut, the vessel may comprise a strut adjustment arrangement configured to retract the strut from the extended position to the retracted position. However, in some embodiments, the struts are not retractable.

The third aspect of the invention also provides a combination of a motor compartment and a submersible structure for a vessel comprising a hull,

wherein the motor pod is configured to be mounted to the hull via a submersible structure,

The recess may be provided as a waist in the housing. The housing or one or more parts of the housing may have a cylindrical shape. The extension of the submersible structure in the longitudinal direction of the housing may be the same as the extension of the recess in the longitudinal direction of the housing along at least one location of the circumference of the housing. The submersible structure may comprise a hydrofoil retaining arrangement by means of which the hydrofoil is mounted to the hull. The hydrofoil retention means may comprise a strut, wherein the hydrofoil and the motor compartment are at substantially the same position along the strut. The post may at least partially surround the housing. The struts and the hydrofoils may extend into recesses in the housing.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

Drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

fig. 1, 2 and 5 show side views of a vessel according to an embodiment of the invention, with a corresponding hydrofoil configuration, wherein some hidden parts are indicated with dashed lines,

figure 3 shows a detail of figure 2,

fig. 4a shows a cross-section of a hydrofoil strut of the vessel in fig. 1, oriented as indicated by arrows IV-IV in fig. 1,

figures 4 b-4 g show a cross-section of a hydrofoil strut of a vessel according to an alternative embodiment of the invention,

figure 6 shows a ship with the hydrofoil configuration of figure 5 viewed from the rear,

fig. 7 shows a cross section of the motor compartment, a part of the strut and the propeller, as indicated by arrows VII-VII in fig. 6,

fig. 8 shows a cross section of the motor bucket, a part of the strut and a part of the hydrofoil, as indicated by arrows VIII-VIII in fig. 7,

figure 9 shows a cross-sectional view as indicated by arrows IX-IX in figure 8,

figure 10 shows a side view of a vessel according to another embodiment of the invention,

figure 11 shows the vessel of figure 10 from the front of the vessel,

figure 12 shows a cross-section of the motor bay, a part of the hydrofoil and a part of the bay securing member of the vessel in figures 10 and 11 similar to the cross-section of figure 8,

fig. 13 shows a side view of a vessel according to an alternative embodiment of the invention, with hydrofoil configuration for half-foil mode,

fig. 14 and 16 show side views of a vessel according to another embodiment of the invention, with a corresponding hydrofoil configuration,

figure 15 shows the vessel with the hydrofoil configuration of figure 14 from the front of the vessel,

figure 17 shows a side view of a vessel according to a further embodiment of the invention,

fig. 18 and 19 show corresponding details similar to those shown in fig. 3, with corresponding strut adjustment means in corresponding alternative embodiments of the invention,

figure 20 shows a side view of a vessel according to one embodiment of the invention,

fig. 21 shows the vessel of fig. 20 seen from the front of the vessel, an

Fig. 22 shows a front view of a vessel according to another embodiment of the invention.

Detailed Description

Fig. 1 shows a hydrofoil vessel 1. The vessel comprises a hull 2.

The vessel comprises a first submersible structure. The first submersible structure comprises a first hydrofoil 301 and a first hydrofoil retaining means 302. The first hydrofoil 301 is mounted to the hull 2 by means of a first hydrofoil retaining arrangement 302. The first hydrofoil 301 is a submerged hydrofoil. The first hydrofoil 301 has an adjustable pitch orientation to change the angle of attack of the first hydrofoil. The first hydrofoil 301 is connected to the hull by means of a first hydrofoil retaining device 302. The first hydrofoil holding means 302 comprises two struts, also referred to herein as first hydrofoil struts 3021. The first hydrofoil 301 may be located close to the centre of gravity CG of the vessel in the direction of travel of the vessel 1.

In some embodiments, the vessel does not include adjustable hydrofoils. In some embodiments, the vessel includes a first hydrofoil passing through the water surface.

The vessel further comprises a second submersible structure. The second submersible structure comprises a second hydrofoil 601. The second hydrofoil 601 is a submerged hydrofoil. The second submersible structure also includes a second hydrofoil retention device that includes a strut 503, also referred to herein as a second hydrofoil strut. The second hydrofoil is mounted to the hull 2 by means of a second hydrofoil retaining arrangement. Second hydrofoil strut 503 is separate from first hydrofoil retention means 302. The second hydrofoil strut is configured to extend downwardly from the hull 2. The second hydrofoil is secured to the lower end of the second hydrofoil strut.

The second hydrofoil is located behind the first hydrofoil 301 when viewed in the direction of straight forward travel of the vessel. The second hydrofoil is configured to support the stern of the hull in a hydrofoil drive mode.

The vessel further comprises a motor compartment 502, described in more detail below. The motor compartment 502 is fixed to the lower end of a second hydrofoil strut 503. As will be described in detail below, the wings of the second hydrofoil 601 extend on opposite sides of the motor compartment. The motor compartment 502 includes a torque generating assembly as described below, and a propeller arrangement including two

counter-rotating propellers

5011, 5012 configured to be driven by the torque generating assembly.

The second hydrofoil strut 503, holding the motor nacelle 502 and the second hydrofoil 601, is pivotally connected to a second hydrofoil strut mounting device 5034 in the form of a bracket fixed to the hull of the vessel by means of a strut swivel bearing assembly comprising two strut bearings 5033. Thus, in addition to the second hydrofoil strut 503, the second hydrofoil retention means includes a strut swivel bearing assembly 5033 and a strut mounting means 5034. Thereby, the second hydrofoil strut can rotate relative to the hull about the rotation axis TA. An actuator (not shown) is provided to perform the rotation. In the case where the actuator is a rudder wheel of a ship, a suitable linkage may be provided between the rudder wheel and the second hydrofoil strut. Thus, the second hydrofoil strut with the motor bucket can be controlled to steer the vessel.

A second hydrofoil strut 503 extends through the hull at a distance forward of the transom 102 of the vessel. For this purpose the vessel is provided with a second hydrofoil strut through opening 101 extending vertically upwards through the vessel from the bottom of the hull. The second hydrofoil strut extends through the second hydrofoil strut through opening 101.

The vessel is adapted to be selectively operated in hydrofoil mode or in planing mode, as described below. The hull 2 has a stern edge 201 configured such that water in contact with the hull in the planing mode of the ship breaks away from the hull at the stern edge. The second hydrofoil strut is located aft of the stern edge. The hull is shaped so that the part of the hull behind the stern edge 201 is above the waterline WL when the boat is at rest.

Furthermore, the vessel is provided with two first hydrofoil strut through openings 103 extending vertically upwards through the vessel from the bottom of the hull. The first hydrofoil stanchions 3021 holding the first hydrofoils each extend through a respective first hydrofoil stanchion through opening 103.

The vessel comprises an adjustment device 510 for the second hydrofoil strut, as described in the following example. The vessel further comprises an adjustment device 310 for the first hydrofoil retaining device, as described in the following example.

Reference is also made to fig. 2.

With the second hydrofoil strut adjustment means 510, the second hydrofoil strut 503 is configured to retract from the extended position shown in figure 1 to the retracted position shown in figure 2. More specifically, second hydrofoil strut 503 is configured to move upwardly along the longitudinal axis of the second hydrofoil strut. Thereby, the

propeller arrangement

5011, 5012 and the second hydrofoil 601 are moved from what is referred to herein as the "deployed position" to the "restrained position". In the deployed and restrained positions, the

propeller devices

5011, 5012 and the second hydrofoil 601 are positioned to be submerged in the water carrying the vessel. However, in the deployed position, the

propeller devices

5011, 5012 and the second hydrofoil 601 are in a position further down, i.e. deeper in the water, than in the restrained position. The deployed position is for the hydrofoil mode of the vessel and the restrained position is for the planing mode of the vessel.

The

propeller arrangement

5011, 5012 and the second hydrofoil 601 are located behind the stern edge 201 in the retracted position of the second hydrofoil strut and in the extended position of the second hydrofoil strut.

In the extended position and in the retracted position, a second hydrofoil strut 503 with a second hydrofoil and propeller arrangement is configured to rotate relative to the hull to steer the vessel, as described in the following examples.

Similarly, first hydrofoil strut 3021, which holds first hydrofoil 301, is configured to retract from the extended position shown in fig. 1 to the retracted position shown in fig. 2 by means of first hydrofoil strut adjustment device 310. More specifically, first foil strut 3021 is configured to move upwardly along a respective longitudinal axis of first foil strut 3021. Thus, the first hydrofoil 301 moves from what is referred to herein as the "deployed position" to the "restrained position".

In the restrained position, the first hydrofoil is above the water surface when the vessel is floating at rest. To this end, the hull comprises a recess 202 which is deep enough to allow the first hydrofoil to move above the water surface. As shown in fig. 2, the front lower edge 2021 of the pocket is lower than the rear lower edge 2022 of the pocket. Thereby, the recess is adapted to form a step in the hull. The step allows air lubrication of the hull when the boat is traveling in planing mode.

Reference is also made to fig. 3.

The second hydrofoil strut adjustment assembly 510 includes a long flexible device 5101 in the form of a rope, wire or cable. A long flexible device 5101 is secured to the second hydrofoil strut 503. The reel 5102, which is configured to be driven by a drive device such as a motor (not shown), is configured to wind a long flexible device to pull up the second hydrofoil leg. The drum 5102 and the drive device form a winch. It will be appreciated that the long flexible device 5101 is secured to a second hydrofoil strut below the drum 5102. A spool 5102 with a drive apparatus is mounted to the second hydrofoil strut holding assembly 5103. The second hydrofoil strut retention assembly 5103 is configured to laterally retain the second hydrofoil strut and is rotatable to rotate the strut 503 in conjunction with the

propeller devices

5011, 5012 for steering the vessel. To this end, the second hydrofoil strut retention assembly 5103 is connected to the strut rotation bearing assembly 5033.

The second hydrofoil strut extends through the second hydrofoil strut retention assembly 5103. The second hydrofoil strut retention assembly 5103 includes two strut retention brackets. Thus, by rotation of the drum 5102, the second hydrofoil strut can be pulled up from the extended position to the retracted position (as shown in fig. 3) by the long flexible device 5101. By rotating the drum in the opposite direction, the second hydrofoil strut is configured to move from the retracted position to the extended position only by gravity.

Reference is also made to fig. 4a.

The main portion of the second hydrofoil strut has a transverse cross-section with hydrodynamic portion 5035 forming a leading edge 5036 and a blunt trailing edge 5037. The leading edge formed by the hydrodynamic portion is rounded. The blunt trailing edge forms a surface 5037 that is straight and perpendicular to the chord line CL of the hydrodynamic portion 5035. Thus, as seen in a transverse cross-section of the strut, the surface forming the blunt trailing edge forms a sharp corner 50351 with the corresponding side surface 50352 of the hydrodynamic portion 5035.

The second hydrofoil strut adjustment means further comprises locking means for locking the second hydrofoil strut in the retracted position and in the extended position. The locking means comprises a first engagement device in the form of a locking protrusion 5104 extending from the blunt trailing edge. Locking projection 5104 is provided by a ridge projecting from and extending along the blunt trailing edge.

The spine 5104 includes a plurality, in this embodiment three, through openings 5105 distributed along the second hydrofoil leg 503. Through port 5105 is configured to receive a second engagement device in the form of a male engagement member 5106, as shown in fig. 3. As also shown by reference numeral 51011 in fig. 3, the lower end of the long flexible device 5101 is secured to a ridge below the through opening 5105. By selectively moving the second hydrofoil strut 503 to align one of the ports 5105 with the male engagement element 5106, the second hydrofoil strut may be positioned and locked in an extended position, a retracted position, or a dry position as described below.

In the extended position of the strut, a portion 5101' of the long flexible device 5101 and the ridge 5104 are located within an extension TE of the surface formed by the blunt trailing edge 5037, which is transverse to the chord line CL of the hydrodynamic portion. Further, long flexible device 5101 and spine 5104 are entirely within a maximum distance MD from blunt trailing edge 5037. The maximum distance is the same as the extension of the hydrodynamic portion along the chord line of the hydrodynamic portion.

Thus, the portion 5101' of the long flexible device 5101 is configured to be positioned behind the blunt trailing edge as viewed in the straight forward direction of travel of the boat. More specifically, when the strut is in the extended position, the portion 5101' of the long flexible device 5101 is located behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel. However, when the stanchion is in the retracted position, at least a portion of the portion 5101' of the long flexible device 5101 is rolled up on the reel 5102 of the winch. In this embodiment, the ridge 5104 is positioned to be behind the blunt trailing edge when viewed in the straight forward direction of travel of the boat. This is the position of the spine whether the strut is in the retracted or extended position. Thus, the ridge 5104 and the portion 5101' of the long flexible device 5101 form what is referred to herein as a shield portion of the strut adjustment device.

As shown in fig. 1, the shelter of the prop regulating device may comprise a wet portion 510w formed by parts of the prop regulating device, which parts are configured to be under the water surface and loaded with its maximum weight when the ship is travelling straight ahead with maximum motor power on the flat water in hydrofoil mode. Preferably, in hydrofoil mode, the entire hull is above the water surface. In fig. 1, the water surface of this hydrofoil pattern is denoted WLH.

The shelter of the strut adjustment means may comprise a static submerged portion 510r which is arranged to be below the water surface when the vessel is statically floating in still water, the strut is in its extended position, and the vessel is loaded with its maximum weight. In fig. 1, the water surface in this case is denoted WLH.

As shown in fig. 1 and 2, first hydrofoil strut adjustment assembly 310 is similar to second hydrofoil strut adjustment assembly 510. That is, with a long flexible device in the form of a rope, wire or cable for each first foil strut 302, and a winch, the first foil strut may be pulled up from the extended position to the retracted position by the long flexible device 5101. The locking device is configured to lock the first hydrofoil strut in either the extended position or the retracted position.

Similar to the second hydrofoil struts, each first hydrofoil strut may have a hydrodynamic portion forming a rounded or pointed leading edge and a blunt trailing edge in a transverse cross-section of the strut. Thereby, a portion of the long flexible device is configured to be positioned behind the blunt trailing edge as seen in the straight forward direction of travel of the vessel. The locking device includes a first engagement device on the blunt trailing edge and a second engagement device configured to engage with the first engagement device to selectively lock the first hydrofoil strut in the extended position or the retracted position. Thereby, the first engagement device of the locking arrangement and the part of the long flexible device form what is referred to herein as a shelter of the first hydrofoil strut adjustment arrangement 310.

Fig. 4b depicts an alternative locking device. The locking means comprises three first engagement devices in the form of locking projections 5104 extending from blunt trailing edge 5037. The locking projections 5104 are provided in the form of posts, each configured to engage a recess of a second engagement device (not shown). The second engagement device is movable toward and away from the locking protrusion 5104 positioned at the second engagement device. Thus, the locking protrusion 5104 and a portion of the long flexible apparatus form what is referred to herein as a shelter of the prop regulating device.

Fig. 4c depicts an alternative strut cross section. The hydrodynamic portion 5035 thereof has a pointed leading edge 5036. With the blunt trailing edge 5037, the hydrodynamic portion forms a supercavity profile. Similar to that shown in fig. 4a, a portion of the long flexible apparatus 5101 for retracting the strut is configured to be positioned behind the blunt trailing edge 5037 when viewed in the straight forward direction of travel of the vessel. Also similar to that shown in fig. 4a, the locking protrusion 5104 is provided by a ridge extending along the blunt trailing edge when viewed in the straight forward travel direction of the boat, and thus, the locking protrusion 5104 is positioned to be located rearward of the blunt trailing edge 5037. Thus, the locking protrusion 5104 and the portion of the long flexible apparatus form what is referred to herein as a shelter of the prop regulating device.

Referring to fig. 4d, a further alternative is shown, which is similar to the scheme shown in fig. 4a except as follows. The spine 5104 has a cavity 5111 extending along the post. The cavity 5111 opens rearward. The cavity 5111 opens in the rearward surface of the ridge.

A portion of the long flexible device 5101 of the second hydrofoil strut adjustment assembly is configured to be positioned within a cavity 5111 on the spine. Thus, the portion and ridge of the long flexible device 5101 form a shelter of the strut adjustment means, which is positioned and configured to be positioned to lie behind the blunt trailing edge 5037 when viewed in the straight forward direction of travel of the vessel.

As shown in fig. 4d, the two surfaces 5037' form a blunt trailing edge 5037. Blunt trailing edge surface 5037' is disposed on the opposite side of ridge 5104. The blunt trailing edge surface 5037' is perpendicular to the chord line CL of the hydrodynamic portion. The blunt trailing edge surface 5037' forms a corner 50351 with a corresponding side surface 50352 of the hydrodynamic portion. The corners are sharp. Thus, they have a small radius, for example less than 1/10 of the width of the blunt trailing edge.

Referring to fig. 4e, another alternative is shown, which is similar to the scheme shown in fig. 4d except as follows. Blunt trailing edge 5037 has a cavity 5111 extending along the struts. The cavity 5111 opens rearward. The cavity 5111 extends from the blunt trailing edge.

A portion of the long flexible device 5101 of the second hydrofoil strut adjustment assembly is configured to be positioned within a cavity 5111 on the blunt trailing edge 5037. Thus, the portion of the long flexible device 5101 forms at least one component of a shroud of the strut adjustment device that is configured to be positioned in the cavity 5111.

Referring to fig. 4f, an embodiment similar to that in fig. 4d is shown, but with the following differences: the blunt trailing surface 5037' is angled so as to partially face the chord line CL of the hydrodynamic portion.

Referring to fig. 4g, an embodiment similar to that in fig. 4d is shown, but with the following differences: the blunt trailing edge surface 5037' is angled so as to partially face away from the chord line CL of the hydrodynamic portion.

Reference is also made to fig. 5 and 6. By means of the second hydrofoil strut adjustment means the second hydrofoil strut 503 is configured to retract from a retracted position to a dry position in which the

propeller arrangement

5011, 5012 and the second hydrofoil 601 are located above the water surface when the vessel is floating at rest. Thereby, the

propeller devices

5011, 5012 and the second hydrofoil 601 are located behind the stern edge 201. More specifically, the

propeller arrangement

5011, 5012 and the second hydrofoil 601 are located between the transom 102 and the stern edge 201. Thereby, fouling of the propeller arrangement and the second hydrofoil may be avoided.

Reference is also made to fig. 7. The motor compartment includes a housing 5021. The housing has a long shape. The housing has a cylindrical outer surface. The housing may be made of metal, for example copper or stainless steel. The housing may be formed by lathe machining.

The torque generating assembly includes two

electric motors

5051, 5052. The motor is coaxially disposed in the housing. The two

propellers

5011, 5012 are each configured to be driven by a respective motor. As suggested, the

propellers

5011, 5012 are located rotationally backward of the motor when viewed in the straight forward direction of travel of the vessel. The propeller includes blades mounted on a propeller hub.

Each motor includes a

stator

5071, 5072. The stator is fixed to an inner surface of the housing 5021. Each motor also includes a rotor 5081, 5082 fixed to a respective one of the two

propeller shafts

5091, 5092. An inner shaft 5091 of the shaft connects the forward motor 5051 of the motor to the stern propeller 5011 of the propeller. The outer shaft 5092 of the shaft connects the rear motor 5051 of the motor to the forward propeller 5012 of the propeller. The inner shaft 5091 extends through the outer shaft 5092.

The

motors

5051, 5052 are configured to be powered by a power source, such as the battery pack 504, as shown in the examples of fig. 1, 2, and 5. In this embodiment, the power supply 504 is located in the hull 2 of the vessel. As shown in fig. 1, 2, 5, and 7, one or more cables 506 are provided for transferring power from the power source 504 to the

torque producing assemblies

5051, 5052. One or more cables 506 extend through the second hydrofoil strut 503. The one or more cables 506 are preferably flexible. Thereby, the cable may bend when the second hydrofoil strut is moved to and from the retracted position. In this embodiment, the cable 506 enters the post 503 at the top end of the second hydrofoil post. Thereby, as shown in the examples of fig. 1, 2, 5, extra cable length is provided in the hull in order to allow lifting of the second hydrofoil leg while retracting, thereby feeding the cable to accommodate the raised second hydrofoil leg.

It will be appreciated that the vessel also comprises cabling for controlling the motors. Similar to the cables, such cabling may also extend through the second hydrofoil strut.

Reference is also made to fig. 8. As suggested, the wings of second hydrofoil 601 extend from opposite sides of motor nacelle 502.

As shown in fig. 7, the outer surface of the housing 5021 includes a recess 5025. The recess extends in the longitudinal direction of the housing, penetrating a central portion of the housing. The recess extends in the circumferential direction of the housing. Typically, the recess may extend at least half way around the circumference of the housing. In this embodiment, the recess 5025 extends through the entire circumference of the housing. The recess is provided as a waist in the housing.

The strut 503 and the second hydrofoil 601 extend into the recess 5025. As shown in fig. 8, to secure the motor bay 502 to the stanchion 503, the lower end of the stanchion forms a fork 5038 that partially surrounds the housing in the recess.

The second hydrofoil 601 is provided as a single piece extending between two wing tips. Thereby, the hydrofoil 601 extends into the recess 5025 of the housing. Thus, the submersible structure formed by second hydrofoil strut 503 and second hydrofoil 601 extends into the recess of the housing.

The hydrofoil comprises a curved portion 6011 of the casing partially surrounded in the recess. The curved portion 6011 connects the wing portions 6012 of the hydrofoils. Thus, the stanchion 503 and hydrofoil 601 together completely surround the housing.

Second hydrofoil strut 503 and second hydrofoil 601 are attached to opposite sides of motor compartment 502 by bolts as shown by line BC in fig. 8. More specifically, from the end of prong 5038, connecting ears 5039 each extend toward a respective one of the wings 6012. The ears 5039 fit into recesses 6013 in the wings 6012. The bolted connection BC extends through the ears 5039 and the recessed portion of the wings 6012.

Thereby, the strut 503 locks the housing in the longitudinal direction of the motor compartment, i.e. along the axis of the propeller, by means of the recess 5025 in the housing. Furthermore, the second hydrofoil 601 is locked in the longitudinal direction of the motor compartment by means of a recess 5025 in the housing. Thus, second hydrofoil 601 provides the function of a nacelle-securing member, which, together with stanchion 503, secures the motor nacelle to the stanchion.

Reference is also made to fig. 9. As shown in the example in fig. 9, the motor bay includes a nose cone 5022 adjacent the housing 5021. The housing 5025 extends in its longitudinal direction from the

propeller arrangement

5011, 5012 to the nose cone 5022.

At the motor compartment, the struts have trailing

edge extensions

5031, 5032 and leading edges that extend above the housing 5021. The

extensions

5031, 5032 have lateral extensions and therefore they extend over corresponding portions of the circumference of the housing.

Along the remaining portion of the housing circumference (over which the

extensions

5031, 5032 do not extend), the extensions of the strut 503 and the hydrofoil 601 in the housing longitudinal direction are the same as the extension RE of the recess 5025 in the housing longitudinal direction. Thus, at the end of the recess in the longitudinal direction of the housing, the strut 503 and the hydrofoil 601 have a boundary in the radial direction of the housing immediately outside the recess, which is the same as the boundary of the housing in the radial direction. Thereby, a smooth transition of the outer surface of the housing to the outer surface of the strut 503 and the hydrofoil 601 is provided.

Fig. 10-12 depict a vessel according to an alternative embodiment of the invention. Similar to the vessel described with reference to fig. 1-8, the vessel comprises a first hydrofoil 301 mounted to the hull 2 by means of a first hydrofoil retaining arrangement 302 comprising two first hydrofoil struts 3021. The vessel further comprises a second hydrofoil 601 mounted to the hull 2 by means of a second hydrofoil retaining arrangement comprising a second hydrofoil strut 503. The second hydrofoil strut 503 is pivotally connected to strut mounting means 5034 fixed to the hull by means of a strut swivel bearing assembly 5033 so that the strut can swivel relative to the hull about a swivel axis.

Unlike the vessel in fig. 1-8, the second hydrofoil strut 503 extends behind the transom 102 of the vessel. The vessel comprises a second hydrofoil strut adjustment means 510 for the second hydrofoil strut 503. The second hydrofoil adjusting apparatus 510 includes a second hydrofoil strut retention assembly 5103. The vessel further comprises a first hydrofoil strut adjustment means (not shown) for the first hydrofoil strut.

Similar to the above, second hydrofoil strut 503 is configured to retract from the extended position shown in fig. 10 and 11 to the retracted position by means of second hydrofoil strut adjustment means 510. The first hydrofoil strut 3021 is also configured to retract from the extended position as shown in figures 10 and 11. Thereby, the first hydrofoil, the

propeller arrangement

5011, 5012, and the second hydrofoil 601 are moved from the deployed position to the restrained position.

The deployed position is set for hydrofoil mode of the vessel and the restrained position is set for planing mode of the vessel. In the extended position and in the retracted position, the second hydrofoil strut 503 together with the second hydrofoil are configured to rotate relative to the hull to steer the vessel.

Similar to the vessel in fig. 1-8, the vessel comprises a motor compartment 502. Unlike the vessel in fig. 1-8, the motor bay 502 is fixed to the first hydrofoil 301. Thereby, the wings of the first hydrofoil 301 extend on opposite sides of the motor compartment.

As can be seen in fig. 12, the first hydrofoil 301 includes a curved portion 3011 that partially surrounds the housing 5021 in the recess 5025 of the housing. The bent portion 3011 is connected to a wing portion of the hydrofoil. The capsule securing member 303 surrounds the remainder of the housing circumference while extending into the recess 5025. Thus, the tank securing member 303 and the hydrofoil 301 together completely surround the housing.

The capsule securing member 303 and hydrofoil 301 are attached to opposite sides of the motor capsule 502 by bolts as shown by line BC in fig. 12. More specifically, from the end of the trunk securing member 303, the connecting ears 3039 each extend toward a corresponding one of the hydrofoil portions. The ears 5039 fit into the recessed portions of the wings. The bolted connection BC extends through the ears 5039 and the recessed portions of the wings.

Refer to fig. 13. In this embodiment, the first hydrofoil 301 may be in a first, constrained position, as shown in fig. 13, where the first hydrofoil is partially deployed and configured to be submerged. Furthermore, second hydrofoil 601 is also in a first restrained position, in which it is partially deployed and configured to be submerged. The first restraining position of first hydrofoil 301 and second hydrofoil 601 is for the half-wing mode of the vessel. In the half-wing mode, the hydrofoils can generate lift to reduce the friction of the hull against the water. The half-wing mode may be useful in billows.

The first and second hydrofoils may be moved to respective second restraint positions, for example, as shown in fig. 2. The second restraint position may be used for a coast mode. Thereby, the first hydrofoil exits from the water passing the hull during travel. Furthermore, in the second restraining position, the second hydrofoil is still submerged, but above the first restraining position.

Fig. 14-16 depict a vessel according to an alternative embodiment of the invention.

Similar to the vessel described with reference to fig. 1-8, the vessel comprises a first hydrofoil 301 mounted to the hull 2 by means of a first hydrofoil retaining arrangement 302 comprising two first hydrofoil struts 3021. The vessel further comprises a second hydrofoil 601 mounted to the hull 2 by means of a second hydrofoil retaining arrangement comprising a second hydrofoil strut 503. The vessel further comprises a motor compartment 502 secured to the lower end of a second hydrofoil strut 503. The wings of the second hydrofoil 601 extend on opposite sides of the motor bucket. The motor compartment 502 includes a torque generating assembly and a propeller arrangement having two

counter-rotating propellers

5011, 5012. The second hydrofoil strut 503 is pivotally connected to strut mounting means 5034 fixed to the hull by means of a strut swivel bearing assembly 5033 so that the strut can swivel relative to the hull about a swivel axis.

Similar to the above, second hydrofoil strut 503 is configured to retract from the extended position shown in figures 14 and 15 to the retracted position shown in figure 16 by means of second hydrofoil strut adjustment assembly 510. The first hydrofoil strut 3021 is also configured to retract from the extended position shown in figures 14 and 15 to the retracted position shown in figure 16. Thereby, the first hydrofoil, the

propeller arrangement

The deployed position is set for hydrofoil mode of the vessel and the restrained position is set for planing mode of the vessel. In the extended position and in the retracted position, the second hydrofoil strut 503 together with the second hydrofoil and propeller arrangement is configured to rotate relative to the hull to steer the vessel.

Referring to fig. 17, another embodiment of the present invention is shown. This embodiment is similar to the embodiment shown in fig. 14-16 with the following exceptions.

The second hydrofoil strut 503 is configured to tilt about an axis that is substantially horizontal when the vessel is floating in an upright position and substantially transverse to the straight direction of travel of the vessel. Thereby, the second hydrofoil strut can be tilted backwards or forwards. Thereby, the second hydrofoil strut is tilted to adjust the angle of attack of the second hydrofoil 601.

The tilt is provided by tilt bearing 521. The tilt bearing connects the second hydrofoil strut retention assembly 5103 with the strut rotation bearing assembly 5033.

Referring to fig. 18, a strut adjustment device 510 in an alternative embodiment of the present invention is shown.

As in the above-described embodiment, the strut adjustment device 510 includes a long flexible device 5101 in the form of a rope, wire, or cable. The long flexible device 5101 is wound one or more times around a drum or actuation wheel 5102, configured to be driven by a drive device such as a motor. The actuation wheel 5102 may have a rough surface or a toothed circumferential track (not shown) for avoiding slippage of the long flexible device 5101 on the actuation wheel 5102. A spool 5102 having a drive device is mounted to the strut holding assembly 5103.

One end of the long flexible device 5101 is fastened to the stanchion 503 below the actuation wheel 5102. The other end of the long flexible device 5101 is fastened to the stanchion 503 above the actuation wheel 5102. The stanchion extends through the stanchion retaining assembly 5103. The strut holding assembly 5103 includes two strut holding brackets. Pulleys 5107 are provided to guide the long flexible device 5101 from the strut to the actuation wheel 5102, and vice versa.

Thus, by rotation of the actuator wheel 5102 in one direction, the strut may be pulled upward from the extended position to the retracted position (as shown in fig. 18) by the long flexible device 5101. By rotation of the actuator wheel 5102 in the opposite direction, the strut may be pulled down from the retracted position to the extended position by the long flexible device 5101. Thus, in addition to gravity, the stanchion may be pulled downward by the stanchion adjustment device 510, for example, to overcome friction in the stanchion retention assembly 5103.

Similar to the above embodiment, the stay adjusting means includes locking means for locking the stay in the retracted position, the extended position, and the drying position. The locking means comprises a first engagement device provided by a ridge rising from and extending along the trailing edge of the blunt strut. The ridge includes three through openings distributed along the post 503. The through port is configured to receive a second engagement device in the form of a male engagement element 5106.

Refer to fig. 19. It will be appreciated that many alternatives are possible for the strut adjustment means. For example, the strut trailing edge may be provided with teeth 5108 distributed along the trailing edge. Thus, the motorized gear 5019 secured to the post holder assembly can be configured to engage and rotate with the post teeth in order to drive the post up or down. Thus, one location of the strut may have a hydrodynamic portion forming a leading edge and a blunt trailing edge. Thus, teeth 5108 are preferably positioned to be behind the blunt trailing edge when viewed in the straight forward direction of travel of the boat. Thus, at least some of the teeth 5108 form a shield portion of the prop adjustment device. Teeth 5108 may form a first engagement device, and wheel 5109 may form a second engagement device configured to engage with teeth 5108 to lock the strut in the retracted position.

Referring to fig. 20 and 21, other embodiments of the present invention are shown. In some embodiments of the invention, the

struts

3021, 503 are separate from the

foils

301, 601. The embodiment in fig. 20 and 21 is similar to the embodiment shown in fig. 14-16 with the following exceptions. The vessel comprises two first hydrofoils 301. The hydrofoils 301 extend on opposite sides of the plane of symmetry of the hull, partly downwards from the hull and partly outwards, away from the plane of symmetry of the hull. The foil 301 is through the water surface.

Each foil 301 also forms what is referred to herein as a strut 3021. In this embodiment, each foil 301 and the respective strut 3021 are integral. Each hydrofoil therefore has a dual function (disposition) of providing lift to the hull in the hydrofoil mode of the vessel and forming part of the hydrofoil retaining means 302 by which the hydrofoil is mounted to the hull.

The mast adjustment means is configured to retract the mast 3021, i.e. the hydrofoil 301, from the extended position to the retracted position. By retraction, the foil 301 is moved from the deployed position shown in figures 16 and 21 to the restrained position (not shown).

The struts 3021, i.e., the hydrofoils 301, have hydrodynamic portions forming leading edges 3026 and blunt trailing edges 3027. Similar to the embodiments described above, the strut adjustment device includes a long flexible apparatus 3101 configured to pull the strut from the extended position to the retracted position. Thus, the stanchions 3021 are configured to be retracted by lifting one or more of the stanchions along their longitudinal axes.

One portion of long flexible device 3101 extends along blunt trailing edge 3027. Thus, the long flexible device 3101 is positioned behind the blunt trailing edge when viewed in the straight forward direction of travel of the vessel.

Fig. 22 shows a front view of a vessel according to a further embodiment of the invention. The vessel is similar to the vessel described with reference to fig. 10-12, but with the following differences.

The vessel comprises two motor compartments 502. Each motor compartment 502 is secured to a first hydrofoil 301 and a corresponding first hydrofoil strut 3021. Thus, each motor compartment 502 is fixed at the junction between the first hydrofoil 301 and the respective first hydrofoil strut 3021. Thereby, the middle portion of the first hydrofoil 301 and the respective cantilever end portion of the first hydrofoil 301 extend on opposite sides of the respective motor compartment.

Although not shown in detail in fig. 22, similar to the embodiment in fig. 10-12, for each motor compartment 502 the first hydrofoil 301 comprises a curved portion partially surrounding the motor compartment housing in a recess of the housing. The curved portion connects the middle portion of the first hydrofoil 301 with the respective cantilevered end portion of the first hydrofoil 301. The lower end of the respective first hydrofoil strut 3021 extends into the recess while surrounding the remainder of the respective housing circumference. The respective first hydrofoil stanchions 3021 and hydrofoils 301 are connected, for example by bolting, on opposite sides of the respective motor compartments 502.

It will be appreciated that the invention is not limited to the embodiments described above and shown in the drawings; on the contrary, one of ordinary skill in the art appreciates that various changes and modifications can be made that are within the scope of the appended claims.

According to the invention, one or more of the schemes are as follows:

scheme 1: a vessel, comprising:

a ship body (2),

a first hydrofoil (301) mounted to the hull (2) by means of a first hydrofoil retaining device (302),

a second hydrofoil (601) mounted to the hull (2) by means of a second hydrofoil retaining arrangement comprising a strut (503) separate from the first hydrofoil retaining arrangement (302), the strut (503) being configured to extend at least partially downwardly from the hull (2), the second hydrofoil being fixed to the strut,

a torque producing assembly (5051, 5052), and

propeller arrangements (5011, 5012), the propeller arrangements being configured to be driven by a torque producing assembly,

wherein the propeller devices (5011, 5012) are mounted to the strut (503),

wherein the strut (503) is configured to retract from the extended position to a dry position in which the propeller arrangement (5011, 5012) and the second hydrofoil (601) are located above the water surface when the vessel is floating at rest, wherein the configuration to retract the strut (503) from the extended position to the dry position comprises configuring the strut to move along a longitudinal axis of the strut.

Scheme 2: vessel according to solution 1, wherein the strut (503) is configured to be retracted from an extended position to a retracted position in order to move the propeller arrangement (5011, 5012) from a deployed position to a restrained position in which the propeller arrangement is positioned to be submerged in water carrying the vessel, wherein the propeller arrangement is located more downwards in the deployed position than in the restrained position, wherein in the extended position and in the retracted position the strut (503) together with the propeller arrangement (5011, 5012) is configured to be rotated relative to the hull to steer the vessel.

Scheme 3: the vessel according to any of the preceding solutions 1-2, wherein the second hydrofoil (601) is fixed to the strut (503) at a position extending in the longitudinal direction of the strut, which position is within the extension of the propeller arrangement (5011, 5012) extending in the longitudinal direction of the strut.

Scheme 4: a vessel, comprising:

a ship body (2),

a torque producing assembly (5051, 5052), and

a propeller arrangement (5011, 5012) configured to be driven by the torque generating assembly,

wherein the propeller devices (5011, 5012) are mounted to the strut (503),

wherein the strut (503) is configured to retract from the extended position to the retracted position in order to move the propeller arrangement (5011, 5012) from a deployed position to a restrained position in which the propeller arrangement is positioned to be submerged in the water carrying the vessel, wherein the propeller arrangement is located more downwardly in the deployed position than in the restrained position,

wherein in the extended position and in the retracted position the strut (503) together with the propeller arrangement (5011, 5012) is arranged to rotate relative to the hull to steer the vessel,

wherein a first hydrofoil retaining means (302) for mounting the first hydrofoil (301) to the hull is configured to retract from an extended position to a retracted position in order to move the first hydrofoil from a deployed position to a restrained position, wherein the first hydrofoil is located further down in the deployed position than in the restrained position,

wherein the first hydrofoil is in a restrained position configured to be submerged.

Scheme 5: a vessel, comprising:

a ship body (2),

and a motor compartment (502) and a submersible structure (301, 302, 503, 601), wherein the motor compartment (502) is mounted to the hull (2) by means of the submersible structure,

wherein the motor compartment further comprises a housing (5021), wherein the torque generating assembly is disposed in the housing,

wherein the housing comprises a recess (2025), and the submersible structure extends into the recess of the housing,

Scheme 6: vessel according to claim 5, wherein, along at least one point of the circumference of the housing (5021), the extension of the submersible structure (503, 601) in the longitudinal direction of the housing is the same as the extension (RE) of the recess in the longitudinal direction of the housing.

Scheme 7: vessel according to any of the claims 5-6, wherein the submersible structure (503, 601) comprises a hydrofoil retaining device (302, 503), wherein the hydrofoil (301, 601) is mounted to the hull (2) by means of the hydrofoil retaining device.

Scheme 8: vessel according to claim 7, wherein the hydrofoil retaining means (302, 503) comprises a strut (3021, 503), wherein the hydrofoil and the motor compartment are in substantially the same position along the strut.

Scheme 9: the vessel according to any of the claims 5-8, wherein the other element is a strut.

Scheme 10: vessel according to any of the claims 5-9, wherein the hydrofoil and other elements extend into the recess of the hull.

Scheme 11: a combination of a motor compartment (502) and a submersible structure for a vessel comprising a hull (2),

wherein the motor compartment (502) is configured to be mounted to the hull (2) by means of a submersible structure,

Claims

1. A vessel, comprising:

-a hull (2),

-a hydrofoil (301, 601) mounted to the hull (2) by means of a hydrofoil retaining arrangement (302) comprising struts (3021, 503),

-wherein the vessel comprises a prop adjustment device (310, 510) configured to retract the prop (3021, 503) from an extended position to a retracted position in order to move the hydrofoil (301, 601) from a deployed position to a restrained position, and/or to lock the prop in the extended position and/or the retracted position,

-characterized in that the said process is carried out,

-at least a part of the strut has a hydrodynamic portion forming a leading edge (5036) and a blunt trailing edge (5037), wherein a shielding portion (5101', 5104, 5108) of the strut adjustment device is positioned and/or configured to be positioned such that an extension of the shielding portion in a longitudinal direction of the strut is located within an extension of the blunt trailing edge in the longitudinal direction of the strut and such that the shielding portion is located behind the blunt trailing edge when seen in a straight forward direction of travel of the vessel and/or in one or more cavities in the hydrodynamic portion, the one or more cavities (5111) extending from the blunt trailing edge.

2. A vessel according to claim 1, wherein the shielding portions (5101', 5104, 5108) of the strut adjustment means extend transversely to the Chord Line (CL) of the hydrodynamic portion or are configured to extend transversely to the chord line of the hydrodynamic portion no further from the chord line than an extension (TE) of the blunt trailing edge (5037) in a direction transverse to the chord line.

3. A boat according to any of the preceding claims, wherein the shelter (5101', 5104, 5108) of the strut adjustment means (310, 510) is located or configured entirely within a Maximum Distance (MD) from the blunt trailing edge (5037) of 300%, preferably 200%, preferably 100%, preferably 50%, preferably 30%, preferably 20% of the extension of the hydrodynamic portion along the chord line of the hydrodynamic portion.

4. Vessel according to any of the preceding claims, wherein all components of the strut adjustment means which are configured to be located below the water surface when the vessel is travelling in hydrofoil mode are located behind the blunt trailing edge when viewed in the straight ahead direction of travel of the vessel and/or are located in one or more cavities in the hydrodynamic portion which extend from the blunt trailing edge.

5. A boat according to any preceding claim, wherein the boat includes propeller arrangements (5011, 5012) mounted to the strut, wherein the blunt trailing edge terminates above a vertical extension of a propeller disc formed by the propeller arrangements when the boat is floating at rest.

6. Vessel according to any of the preceding claims, wherein the shelter (5101', 5104, 5108) of the prop adjustment device (310, 510) comprises a first engagement apparatus (5104), wherein the prop adjustment device comprises a second engagement apparatus (5106) configured to engage with the first engagement apparatus to lock the prop (3021, 503) in the retracted position.

7. The vessel according to any of the preceding claims, wherein the shelter (5101', 5104, 5108) of the strut adjustment device (310, 510) comprises at least a portion of a long flexible apparatus (5101) extending along the blunt trailing edge (5037), wherein the strut (3021, 503) is configured to be retracted from the extended position to the retracted position by being pulled by the long flexible apparatus.

8. A strut for mounting a hydrofoil (301, 601) to the hull (2) of a vessel, characterized in that the strut comprises one or more components (5104, 5108) for a strut adjustment device (310, 510), the strut adjustment device (310, 510) being configured to retract the strut (3021, 503) from an extended position to a retracted position in order to move the hydrofoil (301, 601) from a deployed position to a restrained position, and/or to lock the strut in the extended position and/or the retracted position, wherein at least a portion of the strut has a hydrodynamic portion forming a leading edge (5036) and a blunt trailing edge (5037), wherein the one or more components (5104, 5108) for the strut adjustment device are located on the side of the hydrodynamic portion comprising the blunt trailing edge in the chord direction of the hydrodynamic portion and/or in one or more cavities in the hydrodynamic portion, the one or more cavities (5111) extending from the blunt trailing edge.

9. The strut of claim 8, wherein said one or more components (5104, 5108) for said strut adjustment device (310, 510) are located within an extension (TE) of the surface formed by said blunt trailing edge (5037) that is transverse to a Chord Line (CL) of said hydrodynamic portion.

10. The strut of any one of claims 8 to 9, wherein said one or more components (5104, 5108) for the strut adjustment device (310, 510) are located entirely within a Maximum Distance (MD) from the blunt trailing edge (5037) of 300%, preferably 200%, preferably 100%, preferably 50%, preferably 30%, preferably 20% of the extension of the hydrodynamic portion along the chord line thereof.

11. The strut of any one of claims 8 to 10, wherein the blunt trailing edge formed by the hydrodynamic portion is formed by one or more surfaces forming one or more angles of 60-120 degrees, preferably 70-110 degrees, in a transverse cross-section of the strut relative to a chord line of the hydrodynamic portion.